''Kokartus'' is an extinct
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of prehistoric
stem-group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...
salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...
(
Caudata
The Caudata are a group of amphibians containing the extant salamanders (Urodela) and all extinct species of amphibians more closely related to salamanders than to frogs. They are typically characterized by a superficially lizard-like appearance ...
) from the Middle Jurassic
Balabansai Formation
The Balabansai Formation (sometimes transcribed Balabansay, also known as Balabansai Svita) is a geological formation in Kazakhstan, Kyrgyzstan and Uzbekistan whose strata date back to the Bathonian and Callovian stages of the Middle Jurassic. D ...
of
Kyrgyzstan
Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the east. ...
.
The absence of clear lines of arrested growth and annuli in long bones suggests that the animals lived in an environment with stable local conditions.
Like other members of
Karauridae
The Karauridae are a family of stem-group salamanders (Caudata) that are known from the Middle Jurassic to Late Jurassic in Central Asia (Kazakhstan and Kyrgyzstan) and Western Europe (United Kingdom). The family includes three members: '' Kara ...
, it is thought to have been
neotenic
Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared ...
.
''Kokartus'' is thought to have fed using
suction feeding
Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...
via the enlargement of the
buccal cavity
The buccal space (also termed the buccinator space) is a fascial space of the head and neck (sometimes also termed fascial tissue spaces or tissue spaces). It is a potential space in the cheek, and is paired on each side. The buccal space is super ...
on small fish and invertebrates, with the well developed palatal dentition (teeth on the roof of the mouth) and marginal teeth helping to grasp prey.
See also
*
Prehistoric amphibian
This list of prehistoric amphibians is an attempt to create a comprehensive listing of all Genus, genera from the fossil record that have ever been considered to be amphibians, excluding purely vernacular terms. The list includes all commonly accep ...
*
List of prehistoric amphibians
This list of prehistoric amphibians is an attempt to create a comprehensive listing of all genera from the fossil record that have ever been considered to be amphibians, excluding purely vernacular terms. The list includes all commonly accepted g ...
References
Prehistoric salamanders
Middle Jurassic amphibians
Prehistoric amphibians of Asia
Prehistoric amphibian genera
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